Re: [PATCH v5 3/4] PCI: Handle IORESOURCE_PCI_FIXED when sizing and assigning resources.
From: Bjorn Helgaas <hidden>
Date: 2015-10-20 14:04:26
Also in:
linux-pci, lkml
On Tue, Oct 06, 2015 at 04:50:37PM -0700, David Daney wrote:
From: David Daney <david.daney-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org> The new Enhanced Allocation (EA) capability support creates resources with the IORESOURCE_PCI_FIXED set. This causes a couple of problems: 1) Since these resources cannot be relocated or resized, their alignment is not really defined, and it is therefore not specified. This causes a problem in pbus_size_mem() where resources with unspecified alignment are disabled. 2) During resource assignment in pci_bus_assign_resources(), IORESOURCE_PCI_FIXED resources are not given a parent. This, in turn, causes pci_enable_resources() to fail with a "not claimed" error. So, in pbus_size_mem() skip IORESOURCE_PCI_FIXED resources, instead of disabling them. In __pci_bus_assign_resources(), for IORESOURCE_PCI_FIXED resources, try to request the resource from a parent bus.
This is fixing two problems; can you just split this into two patches? I think the changelogs will read more easily then. It seems like maybe these fixes should also precede the "add support for EA devices" patch. We already use IORESOURCE_PCI_FIXED in a few cases, and these are probably applicable to them, and if you have the fixes in first, we'll have less of a bisection hole when we add EA support.
quoted hunk ↗ jump to hunk
Signed-off-by: David Daney <david.daney-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org> --- drivers/pci/setup-bus.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 47 insertions(+), 3 deletions(-)diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 508cc56..7239a2c 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c@@ -1037,9 +1037,10 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, struct resource *r = &dev->resource[i]; resource_size_t r_size; - if (r->parent || ((r->flags & mask) != type && - (r->flags & mask) != type2 && - (r->flags & mask) != type3)) + if (r->parent || (r->flags | IORESOURCE_PCI_FIXED) || + ((r->flags & mask) != type && + (r->flags & mask) != type2 && + (r->flags & mask) != type3)) continue; r_size = resource_size(r); #ifdef CONFIG_PCI_IOV@@ -1340,6 +1341,47 @@ void pci_bus_size_bridges(struct pci_bus *bus) } EXPORT_SYMBOL(pci_bus_size_bridges); +static void assign_fixed_resource_on_bus(struct pci_bus *b, struct resource *r) +{ + int i; + struct resource *parent_r; + unsigned long mask = IORESOURCE_IO | IORESOURCE_MEM | + IORESOURCE_PREFETCH; + + pci_bus_for_each_resource(b, parent_r, i) { + if (!parent_r) + continue; + + if ((r->flags & mask) == (parent_r->flags & mask) && + resource_contains(parent_r, r)) + request_resource(parent_r, r);
If request_resource() fails, it seems like it'd useful to know about it. Can you use request_resource_conflict() and add a diagnostic similar to what's in pci_claim_resource()?
+ } +} + +/* + * Try to assign any resources marked as IORESOURCE_PCI_FIXED, as they + * are skipped by pbus_assign_resources_sorted(). + */ +static void pdev_assign_fixed_resources(struct pci_dev *dev)
"assign" seems like the wrong verb here (and above). I think of "assign" as the process where we might change the addresses to which the device responds, seting res->start accordingly. But here, we already know those addresses, and we're merely telling the resource manager what we're using.
quoted hunk ↗ jump to hunk
+{ + int i; + + for (i = 0; i < PCI_NUM_RESOURCES; i++) { + struct pci_bus *b; + struct resource *r = &dev->resource[i]; + + if (r->parent || !(r->flags & IORESOURCE_PCI_FIXED) || + !(r->flags & (IORESOURCE_IO | IORESOURCE_MEM))) + continue; + + b = dev->bus; + while (b && !r->parent) { + assign_fixed_resource_on_bus(b, r); + b = b->parent; + } + } +} + void __pci_bus_assign_resources(const struct pci_bus *bus, struct list_head *realloc_head, struct list_head *fail_head)@@ -1350,6 +1392,8 @@ void __pci_bus_assign_resources(const struct pci_bus *bus, pbus_assign_resources_sorted(bus, realloc_head, fail_head); list_for_each_entry(dev, &bus->devices, bus_list) { + pdev_assign_fixed_resources(dev); + b = dev->subordinate; if (!b) continue;-- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/